This invention relates to apparatus for handling disk recording media and in particular to novel improved methods and apparatus for partitioning "disk packs".
Workers in the data recording and related record handling arts are well aware of today's advanced state of the art; e.g., in improved disk recording media and associated record handling equipment. Such equipment has found wide-spread favor, for instance, as related to "flexible" or "floppy" disks, but heretofore will be recognized as adapted to handle only single-disk cartridges, as opposed to multi-disk media, (such as a stacked array of floppy disks). The present invention is intended to supplement improved disk handling equipment adapted to handle such multi-disk media, providing means to separate and partition the disks from one another.
Workers are well aware that, along with their advantages, "floppy disk" media present other problems. Some workers have despaired of finding any simple, practical means of accessing individual selected recording surfaces in a "floppy disk pack" in the precise, rapid, repeatable manner that is typically required -- this principally because a floppy substrate seemed so difficult to hold in position and stabilize. And it is not surprising that workers have anticipated tremendous difficulties in precisely positioning a read/write head between two tissue-thin floppy disks, separated by no more than a few mils, let alone doing so quickly and simply. Also, these flexible records present problems of dimensional instability and variations, such as from their varying responses to thermal effects and from discrepancies in manufacturing tolerances.
Thus, even if one could reasonably expect to position each floppy disk in a stack at a constant reference position relative to the other disks, the prospect of quickly and accurately "finding" a "selected" one of the disks and contacting it with a transducer assembly, has seemed dismal. Accordingly it was surprising to discover a comparatively simple, convenient, and inexpensive means of manipulating such floppy disk packs to afford transducer access according to the invention. This invention is intended to provide means with associated "floppy pack" processing equipment; which is adapted to automatically open and spread a flexible disk pack jacket to automatically partition the stack of disks, and to give satisfactory access to a transducer assembly, etc. The present invention is adapted to accomplish these objectives with automatic equipment which is relatively simple, yet cost-effective, while presenting no danger of damaging or defacing the recording characteristics of the thin plastic disk sheets.
Now, workers dealing with flexible disk media have resorted to special means for packaging the disk, as well as for accessing it. They have typically provided complex containment structures and associated partition means. It has been found that flexible disks may be stacked directly upon one another in a jacket, yet still be manipulated and partitioned -- according to the invention -- relatively simply and conventionally, for transducer access -- all this without compromising such characteristic "floppy disk advantages", as compactness, ready transportability, low cost, etc.
With increased use of such flexible disk media the "removeability" and "interchangeability" of associated unit records has become increasingly important. Workers are aware that the disks which are readily removed and exchanged afford greater flexibility and versatility in use as compared with a fixed-installation disk, or disk pack -- e.g., the recorded data may be stored "off-line" and read-out later on call. Also an interchangeable disk should be processable interchangeably on any drive unit of a certain type. Such removeability and mobility of flexible disk media has its price, however; for instance, it typically requires relatively complex disk-loading hardware, disk packaging means (insuring protection against contamination and for security of data); and positioning means (for the accurate, repeatable transducer carriage to any disk) with associated control electronics (e.g., arranged to reliably and repeatably "find" any prescribed track on any floppy disk injected into the machine). The present invention is directed toward providing equipment for so handling an integral flexible disk pack in a manner that can process any cartridge interchangeably, and meets the cited problems and objectives, while still satisfying countervailing objectives of reasonable cost, relative convenience and simplicity of implementation and the like.
Workers will recognize that one of the principle difficulties that arise when one deals with a "floppy disk" is its vulnerability to defacement. The typical thin compliant plastic disk appears relatively fragile and rather susceptible to damage by some fairly common physical hazards -- such as rupture by impact or sliding contact with a head carriage, with a "separator knife", or with an access-arm on a disk handling assembly, or by other sharp edges. This invention effects a quick, yet simple and accurate pack-splitting using none of such prior art techniques and avoiding these hazards.
Now, while the cost of the disk (cartridge) is relatively inconsequential, the value of the data stored thereon may be tremendous -- such that if the recording surface is so defaced or destroyed by such contact that data is lost, the efficiency and security of an entire associated data processing system may be seriously impaired. The present invention is designed to facilitate the use of such multi-disk flexible media, while yet handling it safely and alleviating, or eliminating, such risks to data integrity. A further object is to effect this by methods, and associated means, which are nonetheless simple, convenient and readily available. Yet a further object is to accomplish this with methods and means that are nonetheless practically interchangeable with those used for conventional single-disk handling equipment.
Some general prior art approaches to the problem of access to a stack of recording disks may be gleaned from consideration of U.S. Pat. No. 3,509,533 to Krijnan and U.S. Pat. No. 3,618,055 to Van Acker; these involving disk separation by pneumatic means involving conduit which admit pressurized gas through a slotted spindle -- an approach more complicated than most workers care to even consider.
Similar prior art arrangements for handling flexible disks may be seen in U.S. Pat. Nos. 3,153,241; 3,225,338; 3,369,227 and 3,573,771; with U.S. 3,678,481 and U.S. 3,815,150 indicating related data handling equipment. Other prior art arrangements for contemplate partitioning a multi-disk stack while it is kept rotating to afford clearance for entry and manipulation of a transducer assembly as may be seen in U.S. Pat. No. 3,130,393 to Gutterman (employing pressurized gas to slide disks apart in a "forced piston" motion, something not really practical for flexible disk media); and in U.S. Pat. No. 2,960,340 to Seidel (involving injection of a probe between stacked phonograph records).
The present invention is designed to provide improved partition methods and apparatus that is simple and unlike such prior art techniques, yet is especially adapted for a stack of disks.
The present invention is particularly designed to accommodate a pack of hole-encoded disks, as well as the positioning manipulations associated therewith -- more specifically, to provide pack-partitioning plunger means, and disk selection and transducer access with automatic equipment.
The present invention overcomes the foregoing and other disadvantages of prior art structures and methods and provides the mentioned and other features and advantages according to a novel design.
The foregoing and other features, objects and advantages, according to the present invention will be more fully appreciated and become more apparent from consideration of the following description of preferred embodiments of the invention, taken in conjunction with the attached drawings wherein like reference symbols denote like parts.